Halothane 5% (0.6 ml/kg) and isoflurane 10% (0.4 ml/kg) in intralipid injected intravenously over one minute were the minimum doses that consistently abolished movement in response to tail clamping in dogs. The depth of anaesthesia was controlled by adjusting the infusion rate. Blood pressure decreased during induction and regained progressively during maintenance with low doses especially with isoflurane. The heart and respiratory rates were increased during maintenance with low doses while a decrease was observed by increasing the depth of anaesthesia that was more prominent with halothane. Recovery achieved after infusion of halothane 5% or isoflurane 10% for 30 minutes, was fast and survivors behaved normally. Lung tissues were macro and microscopically normal. It was concluded that, intravenous administration of halothane 5% or isoflurane 10% induced ultra short general anaesthetic effect and had a safe hemodynamic and respiratory responses especially with isoflurane.